/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.tomcat.jni;

/* Import needed classes */

import java.nio.ByteBuffer;

/**
 * Socket
 *
 * @author Mladen Turk
 */
public class Socket {

    /* Standard socket defines */
    public static final int SOCK_STREAM = 0;
    public static final int SOCK_DGRAM = 1;
    /*
     * apr_sockopt Socket option definitions
     */
    public static final int APR_SO_LINGER = 1;
    /**
     * Linger
     */
    public static final int APR_SO_KEEPALIVE = 2;
    /**
     * Keepalive
     */
    public static final int APR_SO_DEBUG = 4;
    /**
     * Debug
     */
    public static final int APR_SO_NONBLOCK = 8;
    /**
     * Non-blocking IO
     */
    public static final int APR_SO_REUSEADDR = 16;
    /**
     * Reuse addresses
     */
    public static final int APR_SO_SNDBUF = 64;
    /**
     * Send buffer
     */
    public static final int APR_SO_RCVBUF = 128;
    /**
     * Receive buffer
     */
    public static final int APR_SO_DISCONNECTED = 256;
    /** Disconnected */
    /**
     * For SCTP sockets, this is mapped to STCP_NODELAY internally.
     */
    public static final int APR_TCP_NODELAY = 512;
    public static final int APR_TCP_NOPUSH = 1024;
    /** No push */
    /**
     * This flag is ONLY set internally when we set APR_TCP_NOPUSH with APR_TCP_NODELAY set to tell us
     * that APR_TCP_NODELAY should be turned on again when NOPUSH is turned off
     */
    public static final int APR_RESET_NODELAY = 2048;
    /**
     * Set on non-blocking sockets (timeout != 0) on which the previous read() did not fill a buffer
     * completely.  the next apr_socket_recv()  will first call select()/poll() rather than going
     * straight into read().  (Can also be set by an application to force a select()/poll() call
     * before the next read, in cases where the app expects that an immediate read would fail.)
     */
    public static final int APR_INCOMPLETE_READ = 4096;
    /**
     * like APR_INCOMPLETE_READ, but for write
     */
    public static final int APR_INCOMPLETE_WRITE = 8192;
    /**
     * Don't accept IPv4 connections on an IPv6 listening socket.
     */
    public static final int APR_IPV6_V6ONLY = 16384;
    /**
     * Delay accepting of new connections until data is available.
     */
    public static final int APR_TCP_DEFER_ACCEPT = 32768;

    /**
     * Define what type of socket shutdown should occur. apr_shutdown_how_e enum
     */
    public static final int APR_SHUTDOWN_READ = 0;
    /**
     * no longer allow read request
     */
    public static final int APR_SHUTDOWN_WRITE = 1;
    /**
     * no longer allow write requests
     */
    public static final int APR_SHUTDOWN_READWRITE = 2;
    /**
     * no longer allow read or write requests
     */

    public static final int APR_IPV4_ADDR_OK = 0x01;
    public static final int APR_IPV6_ADDR_OK = 0x02;

    public static final int APR_UNSPEC = 0;
    public static final int APR_INET = 1;
    public static final int APR_INET6 = 2;

    public static final int APR_PROTO_TCP = 6;
    /**
     * TCP
     */
    public static final int APR_PROTO_UDP = 17;
    /**
     * UDP
     */
    public static final int APR_PROTO_SCTP = 132;
    /** SCTP */

    /**
     * Enum to tell us if we're interested in remote or local socket apr_interface_e
     */
    public static final int APR_LOCAL = 0;
    public static final int APR_REMOTE = 1;

    /* Socket.get types */
    public static final int SOCKET_GET_POOL = 0;
    public static final int SOCKET_GET_IMPL = 1;
    public static final int SOCKET_GET_APRS = 2;
    public static final int SOCKET_GET_TYPE = 3;

    /**
     * Create a socket.
     *
     * @param family The address family of the socket (e.g., APR_INET).
     * @param type The type of the socket (e.g., SOCK_STREAM).
     * @param protocol The protocol of the socket (e.g., APR_PROTO_TCP).
     * @param cont The parent pool to use
     * @return The new socket that has been set up.
     * @throws Exception Error creating socket
     */
    public static native long create(int family, int type, int protocol, long cont) throws Exception;


    /**
     * Shutdown either reading, writing, or both sides of a socket.
     * <br>
     * This does not actually close the socket descriptor, it just controls which calls are still
     * valid on the socket.
     *
     * @param thesocket The socket to close
     * @param how How to shutdown the socket.  One of:
     * <PRE>
     * APR_SHUTDOWN_READ         no longer allow read requests APR_SHUTDOWN_WRITE        no longer
     * allow write requests APR_SHUTDOWN_READWRITE    no longer allow read or write requests
     * </PRE>
     * @return the operation status
     */
    public static native int shutdown(long thesocket, int how);

    /**
     * Close a socket.
     *
     * @param thesocket The socket to close
     * @return the operation status
     */
    public static native int close(long thesocket);

    /**
     * Destroy a pool associated with socket
     *
     * @param thesocket The destroy
     */
    public static native void destroy(long thesocket);

    /**
     * Bind the socket to its associated port
     *
     * @param sock The socket to bind
     * @param sa The socket address to bind to This may be where we will find out if there is any
     * other process using the selected port.
     * @return the operation status
     */
    public static native int bind(long sock, long sa);

    /**
     * Listen to a bound socket for connections.
     *
     * @param sock The socket to listen on
     * @param backlog The number of outstanding connections allowed in the sockets listen queue.  If
     * this value is less than zero, the listen queue size is set to zero.
     * @return the operation status
     */
    public static native int listen(long sock, int backlog);

    /**
     * Accept a new connection request
     *
     * @param sock The socket we are listening on.
     * @param pool The pool for the new socket.
     * @return A copy of the socket that is connected to the socket that made the connection request.
     * This is the socket which should be used for all future communication.
     * @throws Exception Socket accept error
     */
    public static native long acceptx(long sock, long pool) throws Exception;

    /**
     * Accept a new connection request
     *
     * @param sock The socket we are listening on.
     * @return A copy of the socket that is connected to the socket that made the connection request.
     * This is the socket which should be used for all future communication.
     * @throws Exception Socket accept error
     */
    public static native long accept(long sock) throws Exception;

    /**
     * Set an OS level accept filter.
     *
     * @param sock The socket to put the accept filter on.
     * @param name The accept filter
     * @param args Any extra args to the accept filter.  Passing NULL here removes the accept filter.
     * @return the operation status
     */
    public static native int acceptfilter(long sock, String name, String args);

    /**
     * Query the specified socket if at the OOB/Urgent data mark
     *
     * @param sock The socket to query
     * @return <code>true</code> if socket is at the OOB/urgent mark,
     * otherwise <code>false</code>.
     */
    public static native boolean atmark(long sock);

    /**
     * Issue a connection request to a socket either on the same machine or a different one.
     *
     * @param sock The socket we wish to use for our side of the connection
     * @param sa The address of the machine we wish to connect to.
     * @return the operation status
     */
    public static native int connect(long sock, long sa);

    /**
     * Send data over a network.
     * <PRE>
     * This functions acts like a blocking write by default.  To change this behavior, use
     * apr_socket_timeout_set() or the APR_SO_NONBLOCK socket option.
     *
     * It is possible for both bytes to be sent and an error to be returned.
     *
     * APR_EINTR is never returned.
     * </PRE>
     *
     * @param sock The socket to send the data over.
     * @param buf The buffer which contains the data to be sent.
     * @param offset Offset in the byte buffer.
     * @param len The number of bytes to write; (-1) for full array.
     * @return The number of bytes sent
     */
    public static native int send(long sock, byte[] buf, int offset, int len);

    /**
     * Send data over a network.
     * <PRE>
     * This functions acts like a blocking write by default.  To change this behavior, use
     * apr_socket_timeout_set() or the APR_SO_NONBLOCK socket option.
     *
     * It is possible for both bytes to be sent and an error to be returned.
     *
     * APR_EINTR is never returned.
     * </PRE>
     *
     * @param sock The socket to send the data over.
     * @param buf The Byte buffer which contains the data to be sent.
     * @param offset The offset within the buffer array of the first buffer from which bytes are to be
     * retrieved; must be non-negative and no larger than buf.length
     * @param len The maximum number of buffers to be accessed; must be non-negative and no larger
     * than buf.length - offset
     * @return The number of bytes sent
     */
    public static native int sendb(long sock, ByteBuffer buf, int offset, int len);

    /**
     * Send data over a network without retry
     * <PRE>
     * This functions acts like a blocking write by default.  To change this behavior, use
     * apr_socket_timeout_set() or the APR_SO_NONBLOCK socket option.
     *
     * It is possible for both bytes to be sent and an error to be returned.
     *
     * </PRE>
     *
     * @param sock The socket to send the data over.
     * @param buf The Byte buffer which contains the data to be sent.
     * @param offset The offset within the buffer array of the first buffer from which bytes are to be
     * retrieved; must be non-negative and no larger than buf.length
     * @param len The maximum number of buffers to be accessed; must be non-negative and no larger
     * than buf.length - offset
     * @return The number of bytes sent
     */
    public static native int sendib(long sock, ByteBuffer buf, int offset, int len);

    /**
     * Send data over a network using internally set ByteBuffer
     *
     * @param sock The socket to send the data over.
     * @param offset The offset within the buffer array of the first buffer from which bytes are to be
     * retrieved; must be non-negative and no larger than buf.length
     * @param len The maximum number of buffers to be accessed; must be non-negative and no larger
     * than buf.length - offset
     * @return The number of bytes sent
     */
    public static native int sendbb(long sock, int offset, int len);

    /**
     * Send data over a network using internally set ByteBuffer without internal retry.
     *
     * @param sock The socket to send the data over.
     * @param offset The offset within the buffer array of the first buffer from which bytes are to be
     * retrieved; must be non-negative and no larger than buf.length
     * @param len The maximum number of buffers to be accessed; must be non-negative and no larger
     * than buf.length - offset
     * @return The number of bytes sent
     */
    public static native int sendibb(long sock, int offset, int len);

    /**
     * Send multiple packets of data over a network.
     * <PRE>
     * This functions acts like a blocking write by default.  To change this behavior, use
     * apr_socket_timeout_set() or the APR_SO_NONBLOCK socket option. The number of bytes actually
     * sent is stored in argument 3.
     *
     * It is possible for both bytes to be sent and an error to be returned.
     *
     * APR_EINTR is never returned.
     * </PRE>
     *
     * @param sock The socket to send the data over.
     * @param vec The array from which to get the data to send.
     * @return The number of bytes sent
     */
    public static native int sendv(long sock, byte[][] vec);

    /**
     * @param sock The socket to send from
     * @param where The apr_sockaddr_t describing where to send the data
     * @param flags The flags to use
     * @param buf The data to send
     * @param offset Offset in the byte buffer.
     * @param len The length of the data to send
     * @return The number of bytes sent
     */
    public static native int sendto(long sock, long where, int flags, byte[] buf, int offset, int len);

    /**
     * Read data from a network.
     *
     * <PRE>
     * This functions acts like a blocking read by default.  To change this behavior, use
     * apr_socket_timeout_set() or the APR_SO_NONBLOCK socket option. The number of bytes actually
     * received is stored in argument 3.
     *
     * It is possible for both bytes to be received and an APR_EOF or other error to be returned.
     *
     * APR_EINTR is never returned.
     * </PRE>
     *
     * @param sock The socket to read the data from.
     * @param buf The buffer to store the data in.
     * @param offset Offset in the byte buffer.
     * @param nbytes The number of bytes to read (-1) for full array.
     * @return the number of bytes received.
     */
    public static native int recv(long sock, byte[] buf, int offset, int nbytes);

    /**
     * Read data from a network with timeout.
     *
     * <PRE>
     * This functions acts like a blocking read by default.  To change this behavior, use
     * apr_socket_timeout_set() or the APR_SO_NONBLOCK socket option. The number of bytes actually
     * received is stored in argument 3.
     *
     * It is possible for both bytes to be received and an APR_EOF or other error to be returned.
     *
     * APR_EINTR is never returned.
     * </PRE>
     *
     * @param sock The socket to read the data from.
     * @param buf The buffer to store the data in.
     * @param offset Offset in the byte buffer.
     * @param nbytes The number of bytes to read (-1) for full array.
     * @param timeout The socket timeout in microseconds.
     * @return the number of bytes received.
     */
    public static native int recvt(long sock, byte[] buf, int offset, int nbytes, long timeout);

    /**
     * Read data from a network.
     *
     * <PRE>
     * This functions acts like a blocking read by default.  To change this behavior, use
     * apr_socket_timeout_set() or the APR_SO_NONBLOCK socket option. The number of bytes actually
     * received is stored in argument 3.
     *
     * It is possible for both bytes to be received and an APR_EOF or other error to be returned.
     *
     * APR_EINTR is never returned.
     * </PRE>
     *
     * @param sock The socket to read the data from.
     * @param buf The buffer to store the data in.
     * @param offset Offset in the byte buffer.
     * @param nbytes The number of bytes to read (-1) for full array.
     * @return If &ge; 0, the return value is the number of bytes read. Note a non-blocking read with
     * no data current available will return {@link Status#EAGAIN} and EOF will return {@link
     * Status#APR_EOF}.
     */
    public static native int recvb(long sock, ByteBuffer buf, int offset, int nbytes);

    /**
     * Read data from a network using internally set ByteBuffer.
     *
     * @param sock The socket to read the data from.
     * @param offset Offset in the byte buffer.
     * @param nbytes The number of bytes to read (-1) for full array.
     * @return If &gt; 0, the return value is the number of bytes read. If == 0, the return value
     * indicates EOF and if &lt; 0 the return value is the error code. Note a non-blocking read with
     * no data current available will return {@link Status#EAGAIN} not zero.
     */
    public static native int recvbb(long sock, int offset, int nbytes);

    /**
     * Read data from a network with timeout.
     *
     * <PRE>
     * This functions acts like a blocking read by default.  To change this behavior, use
     * apr_socket_timeout_set() or the APR_SO_NONBLOCK socket option. The number of bytes actually
     * received is stored in argument 3.
     *
     * It is possible for both bytes to be received and an APR_EOF or other error to be returned.
     *
     * APR_EINTR is never returned.
     * </PRE>
     *
     * @param sock The socket to read the data from.
     * @param buf The buffer to store the data in.
     * @param offset Offset in the byte buffer.
     * @param nbytes The number of bytes to read (-1) for full array.
     * @param timeout The socket timeout in microseconds.
     * @return the number of bytes received.
     */
    public static native int recvbt(long sock, ByteBuffer buf, int offset, int nbytes, long timeout);

    /**
     * Read data from a network with timeout using internally set ByteBuffer
     *
     * @param sock The socket to read the data from.
     * @param offset Offset in the byte buffer.
     * @param nbytes The number of bytes to read (-1) for full array.
     * @param timeout The socket timeout in microseconds.
     * @return the number of bytes received.
     */
    public static native int recvbbt(long sock, int offset, int nbytes, long timeout);

    /**
     * @param from The apr_sockaddr_t to fill in the recipient info
     * @param sock The socket to use
     * @param flags The flags to use
     * @param buf The buffer to use
     * @param offset Offset in the byte buffer.
     * @param nbytes The number of bytes to read (-1) for full array.
     * @return the number of bytes received.
     */
    public static native int recvfrom(long from, long sock, int flags, byte[] buf, int offset, int nbytes);

    /**
     * Setup socket options for the specified socket
     *
     * @param sock The socket to set up.
     * @param opt The option we would like to configure.  One of:
     * <PRE>
     * APR_SO_DEBUG      --  turn on debugging information APR_SO_KEEPALIVE  --  keep connections
     * active APR_SO_LINGER     --  lingers on close if data is present APR_SO_NONBLOCK   --  Turns
     * blocking on/off for socket When this option is enabled, use the APR_STATUS_IS_EAGAIN() macro to
     * see if a send or receive function could not transfer data without blocking. APR_SO_REUSEADDR
     * --  The rules used in validating addresses supplied to bind should allow reuse of local
     * addresses. APR_SO_SNDBUF     --  Set the SendBufferSize APR_SO_RCVBUF     --  Set the
     * ReceiveBufferSize
     * </PRE>
     * @param on Value for the option.
     * @return the operation status
     */
    public static native int optSet(long sock, int opt, int on);

    /**
     * Query socket options for the specified socket
     *
     * @param sock The socket to query
     * @param opt The option we would like to query.  One of:
     * <PRE>
     * APR_SO_DEBUG      --  turn on debugging information APR_SO_KEEPALIVE  --  keep connections
     * active APR_SO_LINGER     --  lingers on close if data is present APR_SO_NONBLOCK   --  Turns
     * blocking on/off for socket APR_SO_REUSEADDR  --  The rules used in validating addresses
     * supplied to bind should allow reuse of local addresses. APR_SO_SNDBUF     --  Set the
     * SendBufferSize APR_SO_RCVBUF     --  Set the ReceiveBufferSize APR_SO_DISCONNECTED -- Query the
     * disconnected state of the socket. (Currently only used on Windows)
     * </PRE>
     * @return Socket option returned on the call.
     * @throws Exception An error occurred
     */
    public static native int optGet(long sock, int opt) throws Exception;

    /**
     * Setup socket timeout for the specified socket
     *
     * @param sock The socket to set up.
     * @param t Value for the timeout in microseconds.
     * <PRE>
     * t &gt; 0  -- read and write calls return APR_TIMEUP if specified time elapses with no data read
     * or written t == 0 -- read and write calls never block t &lt; 0  -- read and write calls block
     * </PRE>
     * @return the operation status
     */
    public static native int timeoutSet(long sock, long t);

    /**
     * Query socket timeout for the specified socket
     *
     * @param sock The socket to query
     * @return Socket timeout returned from the query.
     * @throws Exception An error occurred
     */
    public static native long timeoutGet(long sock) throws Exception;

    /**
     * Send a file from an open file descriptor to a socket, along with optional headers and
     * trailers.
     * <br>
     * This functions acts like a blocking write by default.  To change this behavior, use
     * apr_socket_timeout_set() or the APR_SO_NONBLOCK socket option. The number of bytes actually
     * sent is stored in the len parameter. The offset parameter is passed by reference for no reason;
     * its value will never be modified by the apr_socket_sendfile() function.
     *
     * @param sock The socket to which we're writing
     * @param file The open file from which to read
     * @param headers Array containing the headers to send
     * @param trailers Array containing the trailers to send
     * @param offset Offset into the file where we should begin writing
     * @param len Number of bytes to send from the file
     * @param flags APR flags that are mapped to OS specific flags
     * @return Number of bytes actually sent, including headers, file, and trailers
     */
    public static native long sendfile(long sock, long file, byte[][] headers, byte[][] trailers, long offset, long len,
            int flags);

    /**
     * Send a file without header and trailer arrays.
     *
     * @param sock The socket to which we're writing
     * @param file The open file from which to read
     * @param offset Offset into the file where we should begin writing
     * @param len Number of bytes to send from the file
     * @param flags APR flags that are mapped to OS specific flags
     * @return Number of bytes actually sent
     */
    public static native long sendfilen(long sock, long file, long offset, long len, int flags);

    /**
     * Create a child pool from associated socket pool.
     *
     * @param thesocket The socket to use
     * @return a pointer to the pool
     * @throws Exception An error occurred
     */
    public static native long pool(long thesocket) throws Exception;

    /**
     * Private method for getting the socket struct members
     *
     * @param socket The socket to use
     * @param what Struct member to obtain
     * <PRE>
     * SOCKET_GET_POOL  - The socket pool SOCKET_GET_IMPL  - The socket implementation object
     * SOCKET_GET_APRS  - APR socket SOCKET_GET_TYPE  - Socket type
     * </PRE>
     * @return The structure member address
     */
    private static native long get(long socket, int what);

    /**
     * Set internal send ByteBuffer. This function will preset internal Java ByteBuffer for
     * consecutive sendbb calls.
     *
     * @param sock The socket to use
     * @param buf The ByteBuffer
     */
    public static native void setsbb(long sock, ByteBuffer buf);

    /**
     * Set internal receive ByteBuffer. This function will preset internal Java ByteBuffer for
     * consecutive revcvbb/recvbbt calls.
     *
     * @param sock The socket to use
     * @param buf The ByteBuffer
     */
    public static native void setrbb(long sock, ByteBuffer buf);

    /**
     * Set the data associated with the current socket.
     *
     * @param sock The currently open socket.
     * @param data The user data to associate with the socket.
     * @param key The key to associate with the data.
     * @return the operation status
     */
    public static native int dataSet(long sock, String key, Object data);

    /**
     * Return the data associated with the current socket
     *
     * @param sock The currently open socket.
     * @param key The key to associate with the user data.
     * @return Data or null in case of error.
     */
    public static native Object dataGet(long sock, String key);

}
